Lewy body

Photomicrographs of regions of substantia nigra in this Parkinson's patient show Lewy bodies and Lewy neurites in various magnifications. Top panels show a 60-times magnification of the alpha-synuclein intraneuronal inclusions aggregated to form Lewy bodies. The bottom panels are 20x magnification images that show strand-like Lewy neurites and rounded Lewy bodies of various sizes. Neuromelanin-laden cells of the substantia nigra are visible in the background. Stains used: mouse monoclonal alpha-synuclein antibody; counterstained with Mayer's haematoxylin

Lewy bodies appear as spherical masses that displace other cell components. The two morphological types are classical (brain stem) Lewy bodies and cortical Lewy bodies. A classical Lewy body is an eosinophiliccytoplasmic inclusion consisting of a dense core surrounded by a halo of 10-nm-wide radiating fibrils, the primary structural component of which is alpha-synuclein. In contrast, a cortical Lewy body is less well defined and lacks the halo. Nonetheless, it is still made up of alpha-synuclein fibrils. Cortical Lewy bodies are a distinguishing feature of dementia with Lewy bodies (DLB), but may occasionally be seen in ballooned neurons characteristic of Pick's disease and corticobasal degeneration,[1] as well as in patients with other tauopathies.[2] They are also seen in cases of multiple system atrophy, particularly the Parkinsonian variant.[3]

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Photomicrograph of the dorsal motor nucleus of the vagus nerve (DmX) in a transverse section along the upper medulla shown to be affected by the abnormally deposited alpha synuclein as part of intraneuronal Lewy bodies found (extreme right): DmX is one of the earliest sites affected by synuclein deposition in Parkinson's disease.[4]